Separation of oils from mixtures with solid substances



Patented Mar. 3, 1931 UNITED STATES PATENT OFFKIE MATHIAS PIER, OF HEIDELIBEBG, AND RUDOLF WIETZEL AND BRUNO ENGEL, 0F LUD- W'IGfSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNORS TO I. G. FARIBENINDUSTRIE AK- TIENGESELLSCHAFT, OF FRANKFORT-ON-THE-MAIN, GERMANY, A. CORPORATION or anarrmnr snrnnam'ron or OILS mom mxrunns wr'rrr SOLID sussrnnons No Drawing. Application filed August 17, 1928, Serial No. 800,383, and in Germany October 25, 1927.

This invention relates to improvements in the separation of oils from mixtures thereof with solid substances.

In many technical processes, namely in the low temperature carbonization, cracking and extraction of carbonaceous materials, and also in the destructive hydrogenation of varieties of coal, tars, mineral oils and the like, and similar processes hereinafter referred to for I the sake of brevity by the term heat treatment of carbonaceous materials, there? are obtained, inter alia, larger or smaller amountsof products consisting of mixtures of oils of a more or less heavy nature with solid substances containing carbon, such for example as charred residues, ash constituents or other .-solid impurities, such as catalysts. in such cases-it is often'diflicult to separate the solid constituents from the oil.

We have now found that the separation of the said solid constituents from the oils is greatly facilitated by centrifuging-the mixture with anaddition of liquids possessing good solvent properties as regards the oil. Such liquids comprise, more particularly aromatic hydrocarbons such as benzene, toluene and xylene, or hydroaromatic substances such as tetrahydronaphthalene, or substances containingchlorine, such as chloroform, methyL ene chlorid, or also mixtures rich in the same such as brown coal tar oils or coal tar oils, or also fractions of, destructive hydrogenation products of thesame. product obtained by the destructive hydrogenation of certain brown coals be centrifuged by itself, no separation is obtained-at .all'an many instances. On the other hand if about 30 per cent of one of the above-mentioned substances be added, separation is eas- 'ily effected with ordinarycentrifuges, some times even in the cold. comparison-with the usual extractiom'this method of working has the special advantage of requiring a far smaller amount of so vent. -The solvent which, under certain conditions, may still re- If, for example, a

which case different solvents may also be employed.

Under certain conditions the procedure may consist in first eliminating a portion of the adherent oil from the mixture under treatment by centrifuging without the addition of a solvent, the oil being displaced, in this case, from the centrifuge by washing with 1 above case the solid substance from which the oil'is to be extracted are free fromwater or contain only so little water that no aqueous suspensions or pastes of the said solid materials are formed.

It isalso advisable, under, certain circumstances, to add wetting agents, such'as nucleoalkylated sulfonic acids of aromatic hydrocarbons, cellulose pitch, saturated and 'unsaturated fatty acids or salts of the same, and the like, which lessen the adhesion between the solid substances and the adherent oils. In some cases, depending on the nature of the oils, it may also be advantageous to work in an alkaline medium, for example with an additionof alkali or of a sulfid of a strongly alkaline metal. When working in the presence of alkaline agents or wettingagents, it

-may in some cases be advantageous to add water or to employ moist initial materials which may even be presentin the form of aqueous astes or suspensions.

The ollowingexamples will further illustrate the nature of the said invention "which however is not limited thereto.

Emmle 1 If a definite quantity of the sludge resulting from the destructive hydrogenation of brown 'coal be centrifuged at 100 ,C. without any addition, although an oil practically .free from coal is obtained, the centrifuged residue will nevertheless still contain about 40 percent of oil. On the other hand, if the sludge be stirred up with 0.5 to 0,6 of-its own weight of benzene, andthe mixture be centrifuged, a pure oil is also obtained after cooling, whilst the residue will contain, apart tion of methylene ch1orid,toluene,- xylene and the like. I

. Example Q The residue obtained in the destructive hydrogenation of brown coal is stirred up" with 30 per cent of a brown coal tar fraction boilingat from 250 to 300 C., together with the same amount of water, to which a little sodium isopropylnaphthalene-sulfonate has been added. On centrifuging the mixtureat 100 C. separation iseasily efi'ected into three layers, namely, residue, water and oil.

Ewample 3 The sludge obtained in the destructive hydrogenation of brown coal is centrifuged at 130 C. without any addition. In this way,

a portion of the oil contained in the sludge is recovered andis run-off, a'residue contain ing from 40 to 45 per cent of matter soluble in benzene being left in the centrifuge. To this is added about one thirdto half its own weight of heavy benzine also resulting from the destructive hydrogenation processfzand' centrifuging is continued. In this waythe maj or portion of the oil still contained in the residue is expelled.'

l Ewample .4

The sludge obtained in the destructive hy-, drogenation of brown coal is stirred up with half its weight of heavy benzine, with an addition of 0.25 per cent of olein and 0.25 per cent of ammonia, the mixture being centrifuged at from 90 to 95 C; and rinsed with a little heavy benzine. A practically pure oil is obtained, together with aresidue containing 18 per cent of matter soluble in benzene and consisting chiefly of the added heavy benzine. This can be practically all eliminated from the residue by washing with a hot 0.25 per cent aqueous solution of olein, or Turkey red oil and ammonia until the washing liquid runs away clear and free from benzine. The residue then contains only 1.4 per cent of substances soluble .in benzene,

The oil is recovered from the washing liquid b'y'neutralization or slight acidification, and is drawn oif. If the separated washing liquid be again treated with the corresponding amount of ammonia, it can be used again for washing, with equal efiiciency.

What we claim is j 1. A process for the recovery of'oils from mixtures thereof with solid substances containing free carbon, obtained by heat treatmentof carbonaceous materials, which comprises centrifuging the said mixtures with an addition of liquid aromatic hydrocarbons possessing good solvent properties as regards the oil,

-' 2. A process for the recovery of oils from mixtures thereof with solid substances containing free carbon, obtainedby destructive hydrogenation of carbonaceous materials,

which comprises centrifuging the said mixtures with an addition of a liquid possessing good-solvent properties as regards the oil.

3. Avprocess for the recovery of oils from mixtures thereof with solid substances containing freecarbon, obtained by destructive hydrogenation of carbonaceous materials, which comprises centrifuging the said mixtures with an addition of an organic liquid possessing good solvent properties as regards the oil.

4;. A process for the recovery of oils from mixtures thereof with solid substances containing free carbon,obtained by destructive hydrogenation of carbonaceous materials, which comprises centrifuging the'said mixtures with an addition ofliquid aromatic hydrocarbons-possessing good solvent prope'rties as regards the oil.

5. A process for the recovery of oils from mixtures thereof with solid substances containing free carbon, obtained by heat treat-- ment of carbonaceous materials, whichcomprises centrifuging the said mixtures with an addition of a liquid possessing good solvent properties as regards the oil with an addition of an organic wetting agent.

6. A process for the recovery of oils from mixtures thereof with solid substances con taining free carbon, obtained by heat treatment of carbonaceous materials, which comprisescentrifuging the 'said mixtures with an addition of a liquid possessing good solvent properties as regards the oil'with an addition of 'a' salt of an aromatic'sulfonic acid.

7. A process for the recovery of oils from 'mixtures thereof with solidsubstances containing free carbon, obtained by heat treatment of carbonaceous materials, which'comprises centrifuging the said mixtures with an addition of a liquid possessing good solvent properties as regards the oil with an additionof an organic wetting agent and an alkaline agent.

8. A process for the recovery of oils from mixtures thereof with solid substances containing free carbon, obtained by heat treatment of carbonaceous materials, which comprises centrifuging the said 'mixtures' with an addition of a liquid possessing good solvent properties as regards -he oil with an ad- (flition of sodium iscpropyl naphthalene sulonate.

9. A process for the recovery of oils from mixtures thereof with solid substances containing free carbon, obtained by destructive hydrogenation of brown coal which comprises centrifuging the said mixture with an addition of benzene.

10. A process for the recovery of 011s from mixtures thereof with solid substances containing free carbon, obtained by destructive hydrogenation of brown coal which comprises centrifuging the said mixture with an addition of about its own weight of benzene.

11. A process for the recovery of oils from mixtures thereof with solid substances containing free carbon, obtained by destructive mixtures thereof with solid substances containing free carbon, obtained in the destructive hydrogenation of carbonaceous materials which comprises centrifuging the said mixtures with an addition of a liquid possessing good solvent properties as regards the oil with ansddition of a salt of an aromatic sulphonic ac1 14. A process for the recoverv of oils from mixtures thereof with solid substances containing free carbon obtained in the destructive hydrogenation of carbonaceous materials which comprises centrifuging the said mixtures with an addition of a liquid possessing good solvent properties as regards the oil with an addition of sodium isopropyl naphthalene sulphonate.

In testimony whereof wehave hereunto set our hands.

MATHIAS PIER. RUDOLF WIETZEL. BRUNO ENGEL. 

